Common name: Oarweed

General information

Laminaria digitata, commonly known as Oarweed or Tangle, is a large brown alga that is part of the Laminariaceae family. This seaweed is characterized by its long, strap-like fronds that divide into finger-like segments, resembling the digits of a hand, hence the name 'digitata'. It is a perennial species, with individuals living for several years and growing up to several meters in length.

Oarweed plays a crucial role in its ecosystem, forming extensive underwater forests that provide habitat and shelter for a variety of marine life. It is also of interest for its high iodine content and is used in the production of alginate, a substance used in various industrial applications.

Care

In the context of a marine aquarium, Laminaria digitata can be a challenging species to maintain due to its size and specific requirements. It requires strong water flow, high-quality water with low nitrogen levels, and intense lighting to mimic its natural habitat conditions. It is not commonly kept in home aquariums but can be an interesting addition to large public or research aquariums with cold water systems.

Symbiosis

While Laminaria digitata does not have specific symbiotic relationships like those seen in coral reefs, it does serve as a foundational species in its natural habitat. It provides a complex structure that supports a diverse array of marine organisms, including various invertebrates and fish species.

Habitat

Laminaria digitata is found in the subtidal zones of the North Atlantic Ocean. It prefers cold, nutrient-rich waters and is commonly found at depths ranging from the lower intertidal zone to about 20 meters, where it anchors to rocky substrates using a holdfast. Geographically, it is distributed from the Arctic Circle to the North Atlantic coasts, including the North Sea and the western Baltic Sea.